A new crystalline porous superacid material was prepared by sulfation of a Hf-MOF constructed from a 6-connected Hf node and 1,3,5-benzenetricarboxylate. The new superacid MOF with the presence of sulfate groups coordinated to a Hf-oxo cluster as superacid sites was found to be an effective heterogeneous catalyst for solvent-free heterocyclization for benzoxazole synthesis.

中文翻译：

---

一种新型的基于acid的超强酸金属-有机骨架，作为无溶剂条件下合成苯并恶唑的高活性多相催化剂

通过硫酸化由6连接的Hf节点和1,3,5-苯三羧酸酯构成的Hf-MOF，制备了一种新型的结晶多孔超酸材料。发现具有硫酸根基团的新的超酸MOF与Hf-氧代簇配位，作为超酸位点，是一种有效的多相催化剂，可用于苯并恶唑合成的无溶剂杂环。